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really benefit from an engine swap. The Fox, like any other VW (or
any car for that matter) also follows the same general rules.
engine to choose
The main problem
is that the engine is mounted longitudinally, rather than transversely
like in Jettas and Golfs. This means that the exhaust and intake
are specific to the Fox (and older Volkswagens like the B1, B2, and other
Having said this,
though, there are Foxes out there running on more than the stock 1.8L 8v
I'll try to get more
information on these, but it isn't easy come across information on this.
From what I've heard, here are engines that have been swapped into Foxes
(all referring to VW engines):
stock Fox 1.8L block
with Jetta 16v head
Scirocco 1.8L 16v with
Passat V6 twin turbo
with Quantum Synchro system (this is a 300-400 HP rally Fox)
2.0L carburated Santana
engine (into a Brazilian 1983 VW Voyage)
I've heard rumours that
someone has swapped in an Audi I-5 engine
For this to work, the
front of the engine bay would have to be extended, which is definitely
not worth the time and money involved.
This depends on
How much power you want
to get out of the new engine
How much work you're
willing to put in or pay for
How much money you have
These engines are exactly
the same size as the stock Fox engine and you will have no clearance problems
whatsoever. In order for this to be worthwhile, the engine should
come out of a Golf GTI or Jetta GLI, so that it will have a more power
than the Fox engine.
This engine should also
fit right in without major problems. But you will have problems with
the exhaust - the exhaust manifold is different than on 8v engines, which
means than the VW Dasher/Audi Fox manifold upgrade won't work. The
stock 16v exhaust manifold should fit, but you'll need a custom downpipe
to connect it to the rest of the exhaust. The intake manifold might
also pose a problem, as it will either point directly at the battery, or
at the radiator support.
Keep in mind, that a
16v engine requires more maintenance, and it costs about twice as much
to modify one when compared to an 8v.
Installing a 16v head
on the Fox's stock 1.8L bottom end has been done, but it is a LOT of work!
The coolant channels do not line up between the 8v and 16v heads, and there
are many more areas where custom work has to be done. It is not recommended
to duplicate this.
Overall, 16v is not
the way to go in a Fox, due to the fabrication involved. With the
money you would spend on making a custom exhaust manifold and/or downpipe,
you can build an 8v to have as much, if not more power than a stock 16v.
I have no info on this
one yet, but it seems that it's the same size as all of VW's 1.8L engines,
so it should fit right in. Audi A4s and VW Passats have a longitudinal
Audi 80 2.0L 8v aka
"Bubbleblock" [engine code 3A]
This seems to be the
best choice for a combination of good power, ease of installation and price.
The Audi 80's 2.0L 8v is the only of VAG's 2.0L engines that isn't taller
than the 1.8L ones. This means that it will bolt right up in the
Fox's engine bay. It also uses CIS-E fuel injection, so it should
not be too difficult to get it working. You may even be able to use
to stock Audi 80 exhaust manifold and dual downpipe, but I'm not certain.
On an Audi 80 engine, the fuel injectors are in the intake manifold, and
not in the head.
2.0L 8v aka "Tallblock"
This is what all other
VW 2.0L engines are - they are 16mm taller than the 1.8L ones. This
means that you could run into clearance problems on the underside of the
This upgrade has, however,
been done in 2 Foxes that I know of. About the only drawback I've
heard about using this engine, is that it is not as quick to rev as the
This should be possible
to do with enough time and money, with emphasis on money. Since Foxes
never came with VR6s, custom mounts and just about everything else will
have to be fabricated. Furthermore, it is highly doubtful that a
stock longitudinal transmission can take that much power.
Maybe. I only
assume you'd also have to use the stock W8 transmission to handle the 275
This would make the
Fox even more fuel efficient, but I have never heard of anyone completing
On a smallish budget,
I would suggest doing the following:
with any and all comments, and especially if you can add to this page!
I'm listing things
in an approximate order that they should be done, to get progressively
more power, without "wasting" any money on parts that will end up having
to be replaced. I am not including suspension or brake upgrades,
only engine modifications. Once you are into modifying the engine,
upgrading the brakes would be a good idea, so you can stop the car too.
Remove the restrictive
gasket in the exhaust.
Get a good cat-back
exhaust system (2.0" is fine even for a 2.0L, I recommend the Techtonics
Get a dual-outlet exhaust
manifold + corresponding downpipe, and a high-flow catalytic converter
(all can be had from Techtonics as well). An Audi 80 exhaust manifold
and downpipe will provide the best flow, but whether it'll fit is uncertain.
If you have a 1987-1990
Fox, upgrade to the intake manifold and throttle body off a 1991-1993 Fox.
Get a 5-speed transmission,
if not already there. The VW Quantum turbo diesel (code 3M / 9Q)
is the best one to get due to its gearing. The Audi 4000 2P is a
close second, but its 5th gear will have high RPMs on the highway.
The stock Fox 5-speed is the same as the Audi 4000 2N, and is still a definite
improvement over the stock 4-speed.
Get a sport camshaft.
Here you will have to decide whether you will stick with the stock hydraulic
lifters, or end up getting/building a solid-lifter cylinder head.
For maintenance-free operation, stay with hydraulic lifters, but if you
want to end up running a really wild camshaft, you'll have to switch to
solid lifters. Get an adjustable cam gear with it, to control where
the powerband will lie.
Remove rev limiter (only
possible on 1987-1990 Foxes).
Get more fuel to the
engine (4.0 bar fuel pressure regulator on 1991-1993 Foxes).
Getting a cone-style
air filter may help a bit (only possible on 1991-1993 Foxes), as long as
you get cold air to it. On 1987-1990 cars, get a drop-in K&N
panel filter. Drilling holes in the airbox will help a bit, but don't
expect any noticeable gains in power.
Build a cylinder head.
Budget will dictate what you can do - oversized valves, port and polish,
cc'ing, decking, sport valve springs, and so on.
A 2.0L high compression block will yield some very noticeable power.
After all of this, you
can do some more shaving of the head (and block) for even higher compression,
a wilder camshaft, cold air intake with an intake manifold spacer, play
around with the mixture, and ignition- and camshaft timing, stiffer engine
mounts, suspension, a lighter flywheel, lightened crankshaft, smaller-diameter
Thanks for David
Marshall, Philip Amshad, Peter Woodbury and others for telling me about
the engine swaps. If anyone wants to donate an engine to me for a
project Fox, feel free to do so :)
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